Summer/ˈsʌmər/ Definition 1 of 5Pro Tip 1/3Cultural Activities Summer is often associated with outdoor events, like festivals or picnics. We attended the annual summer music festival. Pro Tip 2/3Vacation Period People frequently take their longest vacations during summer, often to travel. They're off on their summer vacation to Greece. Pro Tip 3/3Leisure Time Summer is commonly used to symbolize relaxation and leisure time activities. I can't wait for summer to enjoy some time by the beach.